Although providing accessible online services to people with disabilities is a legal requirement in the U.S for the federal government and highly recommended for other government agencies, severe accessibility issues persist on E-government portals. One potential cause of this problem is that the government lacks strong incentives to adopt a higher accessibility standard because people with disabilities constitute a small proportion of E-government users. By demonstrating that website accessibility is positively associated with usability, this study provides a potential solution to incentivize the government to adopt a higher accessibility standard. To test the relationship between accessibility and usability, 342 county government online portals were selected by a stratified sampling method. The conformance of the homepage of the websites to the WCAG 2.0 accessibility standard was evaluated using an automated tool. Then, an 18-item heuristic checklist was assembled based on prior...